N-(Benzenesulfonyl) thiocarbamates - herbicidal antidotes

ABSTRACT

N-(substituted and unsubstituted benzenesulfonyl) thiocarbamates as new compositions of matter useful as active herbicidal antidotes to protect various crops from injury when used with a thiocarbamate herbicide; improved herbicidal compositions and utility of said compositions employing N-benzenesulfonyl thiocarbamates having the formula ##STR1## wherein X is hydrogen, methyl, chloro, bromo, or methoxy; n is an interger 1 to 3, inclusive; R 1  is hydrogen or methyl; and R 2  is alkyl having from 1 to 4 carbon atoms, inclusive, methylthio-p-chlorobenzenesulfonyl carbamate, benzyl or 4-chlorophenyl; provided that when X is hydrogen and R 1  is methyl, the R 2  is other than ethyl.

This is a division of application Ser. No. 108,890, filed Dec. 31, 1979now U.S. Pat. No. 4,297,295, which application is a division of Ser. No.723,251, filed Sept. 17, 1976, now abandoned, which is acontinuation-in-part application of copending application Ser. No.619,115, filed Oct. 2, 1975, now abandoned.

BACKGROUND OF THE INVENTION

While many herbicides are immediately toxic to a large number of weedpests, it is known that the effect of many herbicides upon importantplant cultivations is either non-selective or not adequately selective.Thus, many herbicides damage not only the weeds to be controlled but, toa greater or lesser extent, the desirable cultivated plants as well.This holds true for many herbicidal compounds which have beencommercially successful and are commercially available. These herbicidesinclude types such as triazines, urea derivatives, halogenatedacetanilides, carbamates, thiocarbamates and the like. Some examples ofthese compounds are described in U.S. Pat. Nos. 2,913,327, 3,037,853,3,175,897, 3,185,720, 3,198,786 and 3,582,314.

The side effect of injury to a cultivated crop by various herbicides isparticularly inconvenient and unfortunate. When used in the recommendedamounts in the soil to control broadleaf weeds and grasses, seriousmalformation or stunting of the crop plants sometimes result. Thisabnormal growth in the crop plants results in loss of crop yield. Thesearch continues for good selective herbicides.

Previous attempts are described to overcome this problem. The treatmentof the crop seed with certain "hormonal" antagonistic agents prior toplanting is described; see U.S. Pat. Nos. 3,131,509 and 3,564,768. Theprotective agents, as well as the herbicides, in these prior processesare largely specific to certain cultivated plant species or in thenature of the antagonistic agents. The prior antagonistic agents havenot been notably successful. The aforementioned patents specificallyexemplify and describe the treatment of seeds employing compounds of adifferent chemical class, not suggestive of the present invention.

The literature describes the preparation of certain N-(benzenesulfonyl)thiocarbamates for which no utility is disclosed. The reference, Hirookaet al., Nippon Kagaku Zasshi: 1970, 91(3) 270(5), CA 73:14369w (1970),relates to the synthesis and reactions ofbis-[N-(phenylsulfonyl)-formimidoyl]disulfides. From certain reactionsof an appropriate disulfide with hydrogen peroxide, there is obtainedN-(phenylsulfonyl)methyl thiolcarbamates. Further, there is reference tocertain alkyl p-toluenesulfonylthiocarbamates used in pharmacologicalevaluations. These latter compounds are by Kriesel, D. C. et al., J.Pharm Sci., 1968, 57(10), 1791-3.

DESCRIPTION OF THE INVENTION

It has been discovered that cultivated crop plants can be protectedagainst injury by thiocarbamate-type herbicides, alone or in mixtures orcombination with other compounds. Further, as an alternative effect, thetolerance of growing plants, more particularly soybeans, to thethiocarbamate herbicides, more particularly S-n-propylN,N-di-n-propylthiocarbamate, can be increased substantially by addingto the soil compound of the type N-(substituted and unsubstitutedbenzenesulfonyl) thiocarbamate which is an effective antidote with saidthiocarbamate herbicide, said compound corresponding to the followingformula ##STR2## wherein X is hydrogen, methyl, chloro, bromo ormethoxy; n is an interger from 1 to 3, inclusive, R₁ is hydrogen ormethyl; and R₂ is alkyl having from 1 to 4 carbon atoms, inclusive,methylthio-p-chlorobenzenesulfonyl carbamate, benzyl or 4-chlorophenyl;provided that when X is hydrogen and R₁ is methyl, then R₂ is other thanethyl.

As a preferred embodiment of the present invention, is a two partherbicide system comprising (1) a first part consisting of at least onethiocarbamate herbicide and (2) a second part consisting of at least onecompound having the formula ##STR3## wherein X is hydrogen, methyl,chloro, bromo, or methoxy; n is an interger from 1 to 3 inclusive, R₁ ishydrogen or methyl; and R₂ is alkyl having from 1 to 4 carbon atoms,inclusive, methylthio-p-chlorobenzenesulfonyl carbamate, benzyl or4-chlorophenyl; provided that when X is hydrogen and R₁ is methyl, thenR₂ is other than ethyl; said compound being antidotally active with saidthiocarbamate herbicide.

Certain of the compounds disclosed herein are considered newcompositions of matter and correspond to the following formula ##STR4##wherein X is hydrogen, methyl, chloro, bromo or methoxy; n is aninterger from 1 to 3, inclusive, R₁ is hydrogen or methyl; and R₂ isalkyl having from 2 to 4 carbon atoms, inclusive,methylthio-p-chlorobenzenesulfonyl carbamate, benzyl or 4-chlorophenyl;provided that when X is methyl, then R₂ is other than alkyl and providedthat when X is hydrogen and R₁ is methyl, then R₂ is other than ethyl.

In the above descriptions, the following embodiment is intended for thevarious alkyl substituent groups. As exemplary of the alkyl portionwithin the preferred embodiment are the following: Methyl, ethyl,n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl, and tert.-butyl.Whereas n can be an interger from 1 to 3, inclusive, preferably n is 3when X is methyl; and n is a parasubstitution of the X moiety.

As an alternative mode of action, the compounds of this invention mayinterfere with the normal herbicidal action of the thiocarbamate-typeand other herbicides to render them selective in their action. Whichevermode of action is present, the corresponding beneficial and desirableeffect is the continued herbicidal effect of the thiocarbamate with theaccompanying decreased herbicidal effect on desired crop species. Thisadvantage and utility will become more apparent hereinafter.

Therefore, the terms "herbicide antidote" or "antidotal amount", ismeant to describe that effect which tends to counteract the normalinjurious herbicidal response that the herbicide might otherwiseproduce. Whether it is to be termed a remedy, interferant, protectant,or the like, will depend upon the exact mode of action. The mode ofaction is varied, but the effect, which is desirable, is the result ofthe method of treating the soil in which a crop is planted. Hitherto,there have been no systems which have been satisfactory for thispurpose.

The compounds of this invention represented by the above formulas can beprepared by several different procedures depending upon the startingmaterials.

The appropriate intermediate, arylsulfonamide, was reacted with an alkylchlorothiolformate in the presence of a hydrogen chloride acceptor toprepare the desired compound. Work-up and purification proceduresinvolved standard methods of extraction, distillation orcrystallization. In most instances, characterization of the structurewas by infrared spectroscopy, nuclear magnetic resonance or massspectroscopy, as well as physical constants.

The compounds of the present invention and their preparation are moreparticularly illustrated by the following examples. Following theexamples of preparation is a table of compounds which are preparedaccording to the procedures described herein. Compound numbers have beenassigned to them and are used for identification throughout the balanceof the specification.

EXAMPLE I Preparation of N-(p-methoxybenzenesulfonyl)-ethylthiolcarbamate

p-Methoxybenzenesulfonamide (11.7 g., 0.64 mole), potassium carbonate(21.5 g., 0.156 mole), and ethyl chlorothiolformate (8.5 g., 0.068 mole)were refluxed in 80 ml. of acetone for eight hours. The cooled mixturewas poured into 350 ml. water and the solution filtered through Celiteand extracted with benzene to remove any unreacted chlorothiolformate.It was then acidified with hydrochloric acid (pH about 2) with cooling.The mixture was extracted with benzene and the extract washed with waterand dried over magnesium sulfate. Removal of the solvent left theproduct as a very viscous oil. There was obtained 8.4 g. (48% theory) ofthe title compound, n_(D) ³⁰ 1.5502.

EXAMPLE II Preparation of N-(p-chlorobenzenesulfonyl)-ethylthiolcarbamate

p-Chlorobenzenesulfonamide (12.0 g., 0.063 mole), potassium carbonate(21.5 g., 0.156 mole), and ethyl chlorothiolformate (8.5 g., 0.068 mole)were refluxed in 75 ml. of acetone for six hours. The work-up was as inExample I. The crude product was triturated with hexane and dried. Therewas obtained 12.4 g. (70% of theory) of the title compound, m.p. 93°-95°C. The structure was confirmed by infrared, nuclear magnetic resonance,and mass spectroscopy.

EXAMPLE III Preparation of N-(benzenesulfonyl)-ethyl thiolcarbamate

Benzenesulfonamide (39.3 g., 0.25 mole), and potassium carbonate (90 g.,0.65 mole) were placed in 300 ml. of acetone and ethylchlorothiolformate (41 g., 0.33 mole) added over several hours. Themixture was stirred one hour at room temperature, then refluxed 12hours. It was cooled, poured into one l. of water and acidified with 100ml. hydrochloric acid. The product was extracted with 250 ml. benzeneand the extract dried over magnesium sulfate. It was filtered and thesolvent removed. Pentane (100 ml.) was added, whereupon the productcrystallized. It was filtered, washed with 50 ml. pentane, and dried at50° C. There was obtained 58 g. (95% of theory) of the title compound,m.p. 100°-103° C. Analysis: N, calculated, 5.72; found, 5.59; Analysis:S, calculated, 26.1; found, 26.24.

EXAMPLE IV Preparation of N-(p-chlorobenzenesulfonyl)-p-chlorophenylthiolcarbamate

p-Chlorobenzenesulfonamide (19.1 g., 0.1 mole), potassium carbonate (30g., 0.22 mole), and p-chlorophenyl chlorothiolformate (22 g., 0.11 mole)in 150 ml. acetone were refluxed and stirred for 10.5 hours. The cooledmixture was poured into one liter water and acidified with acetic acid.The precipitate was filtered, washed with water and dried. There wasobtained 20 g. (55.5% of theory) of the title compound, m.p. 129°-132°C.

Analysis: N, calculated 3.85; found, 4.83.

Analysis: S, calculated, 17.67; found, 17.37.

The following is a table of the compounds which are prepared accordingto the aforementioned procedures. Compound numbers have been assigned tothem and are used for identification throughout the balance of thespecification.

                                      TABLE I                                     __________________________________________________________________________     ##STR5##                                                                     COMPOUND                        m.p. °C.                               NUMBER  n x     R.sub.1                                                                          R.sub.2      or n.sub.D.sup.30                             __________________________________________________________________________    1       1 para-CH.sub.3                                                                       H  C.sub.2 H.sub.5                                                                            104-110                                       2       1 H     H  C.sub.2 H.sub.5                                                                            100-103                                       3       1 para-Cl                                                                             H  4-Clφ    129-132                                       4       1 para-Cl                                                                             CH.sub.3                                                                         C.sub.2 H.sub.5                                                                            1.5643                                        5       1 para-Cl                                                                             H  C.sub.2 H.sub.5                                                                            93-95                                         6       1 para-Br                                                                             H  C.sub.2 H.sub.5                                                                            102-107                                       7       1 para-Cl                                                                             H  n-C.sub.3 H.sub.7                                                                          94-96                                         8       1 para-Cl                                                                             H  i-C.sub.3 H.sub.7                                                                          77-83                                         9       1 para-OCH.sub.3                                                                      H  C.sub.2 H.sub.5                                                                            1.5502                                        10      1 para-Cl                                                                             H  CH.sub.2 φ                                                                             94-96                                         11      3 2,4,6-CH.sub.3                                                                      H  C.sub.2 H.sub.5                                                                            105-108                                       12      1 para-Cl                                                                             H  CH.sub.2 SC(O)S(O.sub.2)4-Clφ                                                          238-239 dec.                                  __________________________________________________________________________

The herbicide indicated in the tables and elsewhere are used at rateswhich produce effective control of undesirable vegetation. The range ofrates employed herein produce representative results within therecommended amounts set forth by the supplier. Therefore, the weedcontrol in each instance is commercially acceptable within the desiredor recommended amount.

It is clear that the class of herbicidal agents described andillustrated herein is characterized as an effective herbicide exhibitingsuch activity. The degree of this herebicidal activity varies amongspecific compounds and among combinations of specific compounds withinthe class. Similarly, the degree of activity to some extent varies amongthe species of plants to which a specific herbicidal compound orcombination may be applied. Thus, selection of a specific herbicidalcompound or combination to control undesirable plant species readily maybe made. Within the present invention, the prevention of injury to adesired crop species in the presence of a specific compound orcombination may be achieved. The beneficial plant species which can beprotected by this method is not intended to be limited by the specificcrops employed in the examples.

The herbicidal compounds employed in the utility of this invention areactive herbicides of a general type. That is, the members of the classesare herbicidally effective against a wide range of plant species with nodiscrimination between desirable and undesirable species. The method ofcontrolling vegetation compries applying an herbicidally effectiveamount of the herein described herbicidal compounds to the area or plantlocus where control is desired. The compositions as set forth in thisinvention include those wherein the preferred active thiocarbamateherbicidal compound is preferably S-n-propyl N,N-di-n-propylthiocarbamate.

An herbicide as used herein means a compound which controls or modifiesthe growth of vegetation or plants. Such controlling or modifyingeffects include all deviations from natural development; for example,killing, retardation, defoliation, desiccation, regulation, stunting,tillering, stimulation, dwarfing and the like. By "plants", it is meantgerminant seeds, emerging seedlings and established vegetation includingthe roots and aboveground portions.

Evaluation Procedures

Flats to be used for growing the crops and weed species were filled withloamy sand soil. Stock solutions of the herbicide and each candidateantidote were prepared as follows:

A. Herbicide--S-n-propyl, N,N-di-n-propyl thiocarbamate--VERNAM®6E--1560 mg. of VERNAM 6E was diluted in 250 ml. of water so that 5 ml.applied to a flat is equivalent to 6 lb/A per flat (based) on thesurface area of a flat).

B. Antidote--of each candidate 78 mg. was dissolved in 20 ml. of acetonewith 1% Tween 20® (polyoxyethylene sorbitan monolaurate) so that 5 ml.when applied by pre-plant incorporation technique (PPI) is equal to 5lb/A per flat.

The herbicide and antidotes were applied to the soil together as a tankmix employing pre-plant incorporation technique. To prepare the combinedtank mix, 5 ml. of the VERNAM® stock solution and 5 ml. of each of theantidote stock solutions were admixed, followed by incorporation intothe soil from the flats during incorporation in a rotary mixer.

One row each of the following weeds and crop was seeded into the treatedsoil in the flats:

Watergrass (Echinochloa crusgalli);

Foxtail (Sataria viridis); and

Soybeans (Glycine max)

The flats were placed on greenhouse benches where temperatures weremaintained between 70°-90° F. The soil was watered by sprinkling toassure good plant growth. Injury ratings were taken 2 and 4 weeks afterthe application was made. Individual flats treated with the herbicidealone were included to provide a basis for determining the amount ofinjury reduction provided by the herbicide antidotes.

The following table includes results as percent protection for the cropaccording to the procedures discussed above. The percent protection isdetermined by a comparison with flats not treated with the candidateantidotes of this invention.

                  TABLE II                                                        ______________________________________                                        Application Method:                                                                        Pre-plant Incorporation - PPI (Tank Mix)                         Crop Species:                                                                              Soybeans (Glycine max)                                           Weed Species:                                                                              Foxtail (Sataria viridis)                                                     Watergrass (Echinochloa crusgalli)                               ______________________________________                                        COMPOUND      PPI (6 lb/A) (Tank Mix)                                         NUMBER        Soybeans   Watergrass                                                                              Foxtail                                    VERNAM 6 lb/A 40*        100*      100*                                       ______________________________________                                        1**           37.5       0         0                                          2             37.5       0         0                                          3             25         0         0                                          4             25         0         0                                          5             50         0         0                                          6             25         0         0                                          7             25         0         0                                          8             50         0         0                                          9             25         0         0                                          10.sup.a      75         0         0                                          11            33         0         0                                          12            50         0         0                                          ______________________________________                                         .sup.a = Pre-plant incorporation of VERNAM® and antidote applied          separately to soil prior to incorporation.                                    *= % injury                                                                   **= % protection                                                         

The thiocarbamate herbicide S-ethyl cyclohexylethyl thiocarbamate andcompound number 6 when applied to the soil together as a tank mixemploying pre-plant incorporation technique, exhibited 50 percentprotection to grain sorghum (milo) planted in the treated soil. That is,the injury to emerging grain sorghum plants was decreased by at least 50percent when grown in soil treated with a tank mix of compound number 6and S-ethyl cyclohexylethyl thiocarbamate. This is compared to grainsorghum (milo) planted in soil containing a treatment of only thethiocarbamate herbicide.

Various other varieties of legumes were tested for antidote activity inconjunction with a representative thiocarbamate herbicide and aN-(benzenesulfonyl) thiocarbamate. Legumes are plants that have asymbiotic relationship with nitrogen fixing organisms. For example,soybeans, varieties of phaeolus vulgarius, peanuts, alfalfa, cloves,peas and the like.

The antidote candidate from the above list of N-(benzenesulfonyl)thiocarbamates compound number 5 was used at the rates of 1 and 2 lb/A.The stock solution used consisted of 39 mg. dissolved in 25 ml. ofacetone, such that 2.5 ml. is equivalent to 1 lb/A when appliedpre-plant incorporated. The representative thiocarbamate herbicide wasEPTC, S-ethyl N,N-dipropyl thiocarbamate. The herbicide stock solutionwas made up by dissolving 1560 mg. of EPTC 6E in 250 ml. water, suchthat 5 ml. of solution was equivalent to 6 lb/A when pre-plantincorporated in the soil.

Navy beans and pinto beans were evaluated in this test. Also present inthe planted flats were the weed species, watergrass and foxtail. Theresults were rated at two and four weeks after treatment and seeding.After two weeks EPTC at 6 lb/A with 1 lb/A and 2 lb/A compound number 5present injured only 10 percent of the navy beans and 0 percent of thepinto bean plants. After four weeks at 1 lb/A navy bean plants wereprotected 23 percent and pinto bean plants were protected 40 percent. At2 lb/A after four weeks navy beans were protected 23 percent and pintobeans 20 percent. The watergrass and foxtail weeds species werecompletely (100 percent) controlled four weeks after treatment with theantidote and herbicide.

Seed Treatment Test

Small flats were filled with Felton loamy sand soil. Soil incorporatedherbicides were applied at this time. The soil from each flat was placedinto a five-gallon cement mixer where the soil was mixed as theherebicides were applied using a predetermined amount of a stocksolution containing 780 mg. of approximately 75 percent activeingredient to 125 ml. of water. Five ml. of stock solution was appliedto the soil in a volumetric pipet. Five ml. of stock solution containedan equivalent of herbicide which equals to six pounds per acre whenapplied to the soil in the flats. After the herbicide incorporation, thesoil was placed back into the flats.

Flats of herbicide-treated and untreated soil were then ready to beplanted. A pint sample of soil was removed from each flat and placednext to each flat for later use in covering up the seeds. The soil wasleveled and rows one-half inch deep were made for planting seeds.Alternating rows of treated and untreated crop seeds were sown. In eachtest, soybean (Glycine max) seeds were planted in each row. Rows wereapproximately one and one-half inches apart in the flat. Seeds weretreated by preparing a stock solution by dissolving 250 mg. of theantidote compound in 2.5 ml. of acetone, then using 0.5 ml. of the stocksolution to treat 10 g. of soybean seed equivalent to 0.5 percent w/w.Antidote compounds can also be applied as liquid slurries and powders ordusts. In some cases, acetone is used to dissolve powdered or solidcompounds so they could be more effectively applied to the seeds.

After the flats were seeded, they were covered with the one pint of soilwhich had been removed just prior to planting. Flats were placed ongreenhouse benches were temperatures ranged from 70°-90° F. Flats werewatered by sprinkling as needed to assure good plant growth. Percentcontrol ratings were taken four weeks after the treatments were applied.

In each test, the herbicide was applied alone, in combination with theseed protectant, and the seed protectant was applied alone to check forphytotoxocity. The untreated adjacent row was employed to observe anybeneficial lateral movement of the antidote compound through the soil.The degree of the effect was noted by comparison with the control.

In this seed treatment test with the herbicide S-n-propylN,N-di-n-propyl thiocarbamate, compound number 5 exhibited 50 percentprotection to the treated soybean seeds. That is, the injury was reducedby at least 50 percent to the emerging soybean plants grown from seedtreated with compound number 5 compared to untreated seed grown in soilcontaining the thiocarbamate herbicide.

The compounds and compositions of this invention were employed ineffective herbicidal compositions comprising the antidote and arepresentative thiocarbamate herbicide as described hereinabove. Theherbicidal compositions were tested in the following manner.

The compositions of the present invention for the protection ofcultivated crop plants comprise an active herbicidal compound and anantidote therefor selected from the above-described compounds. Thecompositions of herbicide and antidote can be prepared by conventionalmethods through the thorough mixing and grinding of the active herbicideagents and the antidote with suitable carriers and/or other distributionmedia, possibly with the addition of dispersion agents or solvents.

The antidote compounds and compositions of the present invention can beused in any convenient form. Thus, the antidote compounds can beformulated into emulsifiable liquids, emulsifiable concentrates, liquid,wettable powder, powders, granular or any other convenient form. In itspreferred form, a non-phytotoxic quantity of an herbicidal antidotecompound is admixed with a selected herbicide and incorporated into thesoil prior to or after planting the seed. It is to be understood,however, that the herbicides can be incorporated into the soil andthereafter the antidote compound can be incorporated into the soil.Moreover, the crop seed itself can be treated with a non-phytotoxicquantity of the compound and planted into the soil which has beentreated with herbicides, or untreated with the herbicide andsubsequently treated with the herbicide. The addition of the antidotecompound does not affect the herbicidal activity of the herbicides.

The amount of antidote compound present can range between about 0.001 toabout 30 parts by weight of antidote compound described herein per eachpart by weight of herbicide. The exact amount of antidote compound willusually be determined on economic ratios for the most effective amountusable. It is understood that a non-phytotoxic quantity of antidotecompound will be employed in the herbicidal compositions describedherein.

What is claimed is:
 1. A herbicidal composition consisting essentiallyof an effective amount of a thiocarbamate herbicide and an antidotallyeffective amount of a compound corresponding to the formula ##STR6## inwhich X is hydrogen, methyl, chloro, bromo, or methoxy; R₁ is hydrogenor methyl; and R₂ is alkyl having from 1 to 4 carbon atoms, inclusive,methylthio-p-chlorobenzene sulfonyl carbamate, benzyl or 4-chlorophenyl;provided that when X is hydrogen and R₁ is methyl, then R₂ is other thanethyl; said compound being antidotally active with said thiocarbamateherbicide.
 2. The herbicidal composition according to claim 1 in which Xis para-methyl, R₁ is hydrogen and R₂ is alkyl.
 3. The herbicidalcomposition according to claim 2 in which R₂ is ethyl.
 4. The herbicidalcomposition according to claim 1 in which X is hydrogen, R₁ is hydrogenand R₂ is alkyl.
 5. The herbicidal composition according to claim 4 inwhich R₂ is ethyl.
 6. The herbicidal composition according to claim 1 inwhich X is para-chloro, R₁ is hydrogen and R₂ is 4-chlorophenyl.
 7. Theherbicidal composition according to claim 1 in which X is para-chloro,R₁ is methyl and R₂ is alkyl.
 8. The herbicidal composition according toclaim 7 in which R₂ is ethyl.
 9. The herbicidal composition according toclaim 1 in which X is para-chloro, R₁ is hydrogen and R₂ is alkyl. 10.The herbicidal composition according to claim 9 in which R₂ is ethyl.11. The herbicidal composition according to claim 9 in which R₂ isn-propyl.
 12. The herbicidal composition according to claim 9 in whichR₂ is isopropyl.
 13. The herbicidal composition according to claim 1 inwhich X is para-methoxy, R₁ is hydrogen and R₂ is alkyl.
 14. Theherbicidal composition according to claim 13 in which R₂ is ethyl. 15.The herbicidal composition according to claim 1 in which X ispara-chloro, R₁ is hydrogen and R₂ is benzyl.
 16. The herbicidalcomposition according to claim 1 in which X is para-bromo, R₁ ishydrogen and R₂ is alkyl.
 17. The herbicidal composition according toclaim 16 in which R₂ is ethyl.
 18. The herbicidal composition accordingto claim 1 in which X is para-chloro, R₁ is hydrogen and R₂ ismethylthio-p-chlorobenzene sulfonyl carbamate.
 19. The herbicidalcomposition according to claim 1 in which X_(n) is 2,4,6-methyl, R₁ ishydrogen and R₂ is alkyl.
 20. The herbicidal composition according toclaim 1 in which R₂ is ethyl.
 21. The method of protecting soybean cropsfrom injury, said injury due to the thiocarbamate herbicide S-n-propyldi-n-propylthiocarbamate, comprising application to the soil in whichsaid crop is to be planted and grown, non-phytotoxic antidotallyeffective amount of a compound corresponding to the formula ##STR7## inwhich X is hydrogen, methyl, chloro, bromo, or methoxy; R₁ is hydrogenor methyl; and R₂ is alkyl having from 1 to 4 carbon atoms, inclusive,methylthio-p-chlorobenzene sulfonyl carbamate, benzyl or 4-chlorophenyl;provided that when X is hydrogen and R₁ is methyl, then R₂ is other thanethyl.
 22. The method according to claim 21 in which X is para methyl,R₁ is hydrogen and R₂ is alkyl.
 23. The method according to claim 22 inwhich R₂ is ethyl.
 24. The method according to claim 21 in which X ishydrogen, R₁ is hydrogen and R₂ is alkyl.
 25. The method according toclaim 24 in which R₂ is ethyl.
 26. The method according to claim 21 inwhich X is parachloro, R₁ is hydrogen and R₂ is 4-chlorophenyl.
 27. Themethod according to claim 21 in which X is parachloro, R₁ is methyl andR₂ is alkyl.
 28. The method according to claim 27 in which R₂ is ethyl.29. The method according to claim 21 in which X is parachloro, R₁ ishydrogen and R₂ is alkyl.
 30. The method according to claim 29 in whichR₂ is ethyl.
 31. The method according to claim 29 in which R₂ isn-propyl.
 32. The method according to claim 29 in which R₂ is isopropyl.33. The method according to claim 21 in which X is para methoxy, R₁ ishydrogen and R₂ is alkyl.
 34. The method according to claim 33 in whichR₂ is ethyl.
 35. The method according to claim 21 in which X ispara-chloro, R₁ is hydrogen and R₂ is benzyl.
 36. The method accordingto claim 21 in which X is parabromo, R₁ is hydrogen and R₂ is alkyl. 37.The method according to claim 36 in which R₂ is ethyl.
 38. The methodaccording to claim 21 in which X is parachloro, R₁ is hydrogen and R₂ ismethylthio-p-chlorobenzene sulfonyl carbamate.
 39. The method accordingto claim 21 in which X_(n) is 2,4,6-methyl, R₁ is hydrogen and R₂ isalkyl.
 40. The method according to claim 39 in which R₂ is ethyl. 41.The herbicidal composition as set forth in claim 1 wherein saidthiocarbamate herbicide is selected from the group S-n-propylN,N-di-n-propyl thiocarbamate, S-ethyl dipropyl thiocarbamate, andS-ethyl cyclohexylethyl thiocarbamate.
 42. The method of protecting acrop from injury, said injury due to a thiocarbamate herbicide selectedfrom the group S-n-propyl N,N-di-n-propyl thiocarbamate, S-ethyldipropyl thiocarbamate, and S-ethyl cyclohexylethyl thiocarbamate;comprising application to the soil in which an herbicidally effectiveamount of said thiocarbamate is used, a non-phytotoxic amount of acompound corresponding to the formula ##STR8## in which X is hydrogen,methyl, chloro, bromo, or methoxy; R₁ is hydrogen or methyl; and R₂ isalkyl having from 1 to 4 carbon atoms, inclusive,methylthio-p-chlorobenzene sulfonyl carbamate, benzyl or 4-chlorophenyl;provided that when X is hydrogen and R₁ is methyl, then R₂ is other thanethyl; said compound being antidotally active with said thiocarbamateherbicide.